Muscle necrosis caused by snake venoms and toxins

Snake bite is often associated with localised soft tissue necrosis. Less frequently victims may suffer extensive muscle damage leading to rhabdomyolysis and the loss of muscle-specific protein. This review describes the organisation and structure of mammalian skeletal muscle, and its response to myotoxic venoms and to isolated pure myotoxic venom fractions. The clinical reports of muscle damage in man following snake bite are discussed, and the various classes of myotoxic toxins are introduced. Muscle damage caused by the toxins is next described, particular emphasis being placed on the correlation between muscle pathology seen at the light level and the morphological changes seen at the level of the electron microscope. Where known, those subcellular components of the muscle fibre that are especially sensitive to assault, and those components that appear to be spared, are identified. The relevance of the selective sparing of some components to the regenerative capacity of the skeletal muscle is considered.